The reason for the drop in the number of cases for anthropometry in 2011 Nepal DHS, was that, it was determined that the sample size would be representative at the domain level (13 eco-development regions) even if it was conducted in a sub-sample of 50% of the household. It was suggested by the sampler that precision for the anthropometry is acceptable even with measures in 1/2 of the HH. Therefore, it was decided to collected information in a sub-sample.

I hope this gives an idea to the case.